Means and method for unweaving in wave weaving looms



Sept. 20, 1966 H. FEND 3,2 73,602

MEANS AND METHOD FOR UNWEAVING IN WAVE WEAVING LOOMS Filed 001;. 12, 1964 4 Sheets-Sheet 1 H. FEND Sept. 20, 1966 MEANS AND METHOD FOR UNWEAVING IN WAVE WEAVING LOOMS 4 Sheets-Sheet 2 Filed Oct. 12, 1964 H. FEND Sept. 20, 1966 MEANS AND METHOD FOR UNWEAVING IN WAVE WEAVING LOOMS Filed Oct. 12, 1964 4 Sheets-Sheet 3 Sept. 20, 1966 H. FEND 3,273,602

MEANS AND METHOD FOR UNWEAVING IN WAVE WEAVING LOOMS Filed Oct. 12, 1964 4 Sheets-Sheet 4 a z a 1 A g United States Patent 3,273,602 MEANS AND METHOD FOR UNWEAVING IN WAVE WEAVING LOOMS Heinrich Fend, Regensdorf, Zurich, Switzerland, assignor to Verwaltungsgesellschaft der Werkzeugmaschinenfabrik Oerlikon, Zurich, Switzerland Filed Get. 12, 1964, Ser. No. 403,195 Claims priority, application Switzerland, Oct. 14, 1963, 12,599/ 63 19 Claims. (Cl. 139-1) The present invention has reference to an improved method of unweaving at a wave weaving loom, wherein during weaving the Weft thread is tied or interlaced at a location between each two shuttles which successively follow one another, and each individual shuttle moving at a spacing behind one another into the warp thread chain has associated therewith its own harness change program effective for at at least one harness change mechanism driven in stepwise manner. The present invention is also concerned with an improved wave weaving loom for carrying out the inventive method which is constructed such that it is possible to weave as well as unweave therewith.

The problem of unweaving exists with every weaving loom. In other words, it must be possible after the rupture of a warp thread or weft thread, generally requiring the withdrawal of one or more already inserted weft threads, to again locate the junction or starting point according to the pattern. Thus, it is not sufiicient to merely turn back the fabric an amount corresponding to the removed thread in order that the fell of the fabric or cloth is again located at the beat-up height. Rather, the apparatus for controlling the harnesses must be appropriately re-adjusted in order that the program for the withdrawn weft threadagain to be inserted--properly repeats. While with conventional weaving looms unweaving can be undertaken in this manner without difficulty because with every harness change rearwardly a weft thread is always again freed throughout the entire fabric width, with wave weaving looms there exists the additional problem of removing the weft thread.

In order to more fully explain this problem mention is made of the fact that, during operation as well as also during standstill, the individual weft threads are always again tied or interlaced at a location between the shuttles, because between each shuttle there occurs a change of shed. It is, therefore, not merely possible to remove a weft thread inserted throughout the entire fabric width by merely permitting reverse running of the harness program. The warp threads are always located in parallelism between each two shuttles, that is, both of the groups which change position just cross. Depending upon the pattern a number of threads also always remain in both terminal positions.

During weaving the shuttles move over the chain of warp threads, for example from the left to the right. 'In front of each shuttle a respective group of warp threads are brought by the harnesses in one or the other terminal position, wherein for the same shuttle the same group distribution remains throughout the entire weaving or fabric width. However, each shuttle, depending upon the pattern, has a different group distribution, determined by the harness control at the moment at which the relevent harness or warp thread is located just above or below the shuttle center of the previous shuttle. These are the extreme positions of the warp threads, and here the control determines if such is to be maintained for the next shuttle, or, if prior thereto, the warp threads controlled by this harness are still to be changed into the other terminal position. Since, in order to produce a pattern, there is always employed a plurality of harnesses arranged behind one another (or with wave weaving looms rows of harnesses 3,273,602 Patented Sept. 20, 1966 with small individual harnesses), it is possible to simultaneously change harnesses from the top towards the bottom and vice versa, or to allow them to remain in one of both terminal positions. The pattern is then determined by the distribution of the raised or lowered harness located over the shuttle center.

Simply to allow the entire loom together with the harness program to run backwards for unweaving would cause the shuttles to move in the opposite direction and the pattern would again unravel backwards, much in the same manner in which it was formed by the harnesses. However, since the weft thread stored in the shuttle can only be removed from such and during reverse motion cannot again be wound-up by such, in order to prevent malfunctions with such an operation, it is necessary to simultaneously remove in succession the temporarily freed weft threads for all shuttles manually. This is unsafe, time-consuming and complicated.

Accordingly, it is a primary object of the present invention to provide an improved method of, and apparatus for, unweaving a fabric woven at a loom, particularly a wave weaving loom, in a relatively simple and uncomplicated manner, the unweaving operation being eflicient from the standpoint of time as well as relatively easy to perform.

Another important object of the present invention is the provision of an improved method of, and apparatus for, unweaving a fabric woven at a loom, particularly a wave weaving loom, such that the faulty location appearing at the woven fabric can be quickly and positively reached, at the same time the program for the pattern restored to a point corresponding to the faulty location, so that upon removal of the fault, typically a ruptured weft or warp thread, weaving can continue exactly according to the prescribed pattern.

Still a further important object of the present invention is directed at the provision of an improved unweaving drive for a loom, particularly a wave weaving loom incorporating a storage mechanism and a harness change mechanism, wherein the unweaving drive is constructed to convert the drive for the storage mechanism into a stepwise drive of opposite rotational sense as well as to step-down the same inrelation to the number of shuttles.

The problems encountered during unweaving, explained above, can be effectively solved by the teachings of the present invention in that, the delivery of weft thread is cut-off, and the harness change commands previously introduced into a harness change mechanism are delivered to the latter in reverse sequence, wherein between each two successive harness change commands as many indexing step spacings are left as there are used shuttles for weaving, with the weft thread which is freed 0r exposed after each command passing through the harness change mechanism being removed from the shed which is now open throughout the entire fabric width, and the aforedescribed process is repeated so often until the location of thread rupture is reached.

The method according to the invention can be particularly carried out at wave weaving looms, which according to the invention are equipped with a controllable program storage mechanism and a transmission device connectable between such storage mechanism and the harness change mechanism in order to extend or prolong a program in relation to the number of shuttles.

Harness change mechanisms and apparatus for driving the same for wave weaving looms have been disclosed in detail in my co-pending United States application, Serial No. 346,976, filed February 24, 1964 and entitled Drive Arrangement With Stepwise Power Take-Off, Particularly Adapted For Utilization With Weaving Looms. The inventive method as Well as the illustrative construction of a weaving loom for the performance of this method will be described in detail on the basis of these known apparatuses. However, since the physical structure and the manner of operation of such apparatus is important in order to comprehend the underlying principles of the present invention, there will hereinafter be described at least enough of the more important components necessary to understand the present invention, with a portion of the relevant figures of the previously mentioned co-pending application being herein reproduced.

Other features, objects and advantages of the invention will become apparent by reference to the following detailed description and drawings in which:

FIGURE 1 schematically illustrates a preferred form of drive arrangement used in the present invention;

FIGURES 2 to 6 are functional diagrams or symbols providing a simplified manner of depicting drive arrangements;

FIGURE 7 schematically depicts a program storage mechanism;

FIGURE 8 schematically depicts a harness change mechanism;

FIGURE 9 schematically depicts an apparatus for weaving and unweaving;

FIGURE 10 illustrates the arrangement of the warp threads and shuttles at the moment of weaving;

FIGURE 11 is a plan view of a chain of warp threads with the shuttles;

FIGURE 12 illustrates the arrangement of warp threads and shuttles at the time of unweaving;

FIGURE 13 schematically illustrates an embodiment of inventive unweaving transmission or drive; and

FIGURE 14 illustrates in cross-section a possible physical construction of the unweaving drive depicted in FIGURE 13.

The basic component or element for the harness change mechanism and for the program command or impulse storing mechanism is a drive arrangement with stepwise power take-off, hereinafter generally referred to as operating cell or zone.

FIGURE 1 depicts such a drive arrangement or mechanism wherein stepwise indexing wheels or gears 1, 2, 3, 4 and 5, are stationarily mounted, in each instance, upon a rotatably supported shaft 6, 7, 8, 9 and 10, respectively, for convenience in illustration such shafts only have been schematically depicted. The stepwise indexing wheels 1, 2, 3, 4 and 5, in the present embodiment, are assumed to embody gears, the toothed rim of which is always interrupted by a suitable recess 11. Each indexing gear 1, 2, 3, 4 and 5 is operably associated with drive means, in this case a drive gear 12, 13, 14, 15 and 16, respectively, and which in the illustrated position of FIGURE 1 of the relevent indexing gear is not in meshing arrangement therewith by virtue of the provision of the aforementioned recess 11. However, after a small rotation out of the illustrated position, the gear-tooth system of the indexing gears 1, 2, 3, 4 and 5 meshes with the corresponding gear-tooth system of the associated drive gear 12, 13, 14, 15 and 16, respectively, whereupon the relevent indexing gear is entrained for one revolution by its associated drive gear or wheel. Moreover, it will be understand that the drive gears 12 to 16 are given in synchronism with one another.

As can further be seen by inspecting FIGURE 1, the indexing gears '1 to 5 are connected in series by what has been conveniently termed herein starting or starter mechanisms 17, 18, 19 and 20, in each case arranged between two neighboring indexing gears. An additional starting mechanism 21 is connected in front of the indexing gear 1. Each starting mechanism is comprised of a primary element 22 and a secondary element 23, both constructed in the form of a cam disk. The primary element 22 of the starter mechanism 17 and the secondary element 23 of the starter mechanism 21 are rigidly seated upon the ends of the shaft 6, whereas the secondary element 23 of the starter mechanism 17 and the primary element 22 of the starter mechanism 21 are rigidly arranged upon the shafts 7 and 24, respectively. The illustrated arrangement, as should be clearly evident from the drawing, is effected such that during a revolution of the shaft 24 or 6 respectively, in the direction of rotation indicated by the arrows, the entrainment cams or cam portions 22a of the primary elements with a given rotational position come to act upon the entrainment cams or cam portions 23a of the secondary elements, to thereby effect entrainment of the corresponding secondary element 23 through a predetermined angle of rotation.

Furthermore, the arrangement is constructed such that, for example, the starter mechanism 17 first comes into operable engagement or activity after a time lapse, that is after the indexing gear 1 has moved out of its illustrated rest position and has begun an indexing step. It should be apparent that the same holds true for the remaining starter mechanisms 18, 19, 20, the primary element 22 of which is always rigidly arranged upon the shaft of the indexing gear of the previous row and the secondary element 23 of which is always rigidly arranged upon the shaft of the indexing gear of the subsequent row. The shaft 10 of the indexing gear 5 carries at its end directed away from the starter mechanism 20 a primary element 22 adapted to cooperate with a secondary element (not illustrated), to thereby permit continuation of the row of interconnected indexing gears. On the other hand, this primary element 22 can cooperate with the secondary element 23 of the starter mechanism 21; such possibility will be considered in greater detail as the description proceeds. At any rate, it can be ascertained and it should also be readily apparent that, with the illustrated arrangement an optional number of indexing gears 1, 2, 3 etc. can be connected in series.

In the embodiment depicted in FIGURE 1, the indexing gears 1, 2, 3, 4 and 5 are located in their rest position, whereas the associated drive gears 12, 13, 14, 15 and 16 rotate continuouslyand as mentioned-in synchronism. Assuming now that the shaft 24 provided with the primary element 22 of the starter mechanism 21 is started to rotate in the direction of the associated arrow, then, after a predetermined angular rotation, the secondary element 23 of this starter mechanism 21 is entrained, the indexing gear 1 provided with the associated drive gear 12 brought into meshing engagement and entrained by such drive gear 12 through one revolution, that is, for a switching step. After a predetermined angle of rotation and, thus, with a time delay after initiation of a switching or indexing step, the cam 22a of the primary element 22 of the starter mechanism 17 becomes elfective at the associated secondary element 23, whereupon the secondary element 23 together with shaft '7 is placed in rotation in the direction denoted by the associated arrow. Consequently, the indexing gear 2 is placed into meshing engagement with the drive gear 13, and entrained by the latter through a switching step. The thus resultant rotation of the primary element 22 of the starter mechanism 18 causes, with previously mentioned time-delay and via, the secondary element 23 of the starter mechanism 18, engagement of the indexing gear 3 with the drive gear 14, whereupon this indexing gear 3 is also entrained, through one indexing step. After the beginning of this indexing step the starter mechanism 19 becomes positively connected in the manner previously described, the indexing gear 4 placed in rotation and entrained by its drive gear 15. As a result, the primary element 22 of the starter mechanism 20 which rotates therealong effects the start of indexing wheel 5 at the proper time. In this manner, an indexing command imparted to the first indexing gear of the indexing gear row or the chain of indexing gears is delivered with a time-delay to the subsequent indexing gears, so that the indexing gears perform an indexing step one row after the other in spaced time intervals. The indexing command, thus, travels or wanders through the rows of indexing gears, whereby the operation can also be viewed in a manner that basically a movement, namely, the indexing movement or a movement derivable therefrom, travels through the rows of indexing gears.

Now, as soon as the first indexing command is already located at a given distance from the first operating zone or cell embodied by the indexing gear 1 with the associated elements, a further indexing command can be introduced into this first operating cell. The only condition decisive for the period of time in which a further indexing command can be introduced is that such will only first then be delievered to the second operating cell when the indexing gear 2 has come to rest. Apart from such, however, the period of time for introduction of a new switching or indexing command can basically be freely selected. It is also possible, under certain prerequisities, to impart to the first cell indexing commands with desired sequence in time, whereby the indexing commands and therewith the indexing sequence depicted by suchcomparable to a pulse sequence or pulse train-travel through the rows of operating zones or cells. Within the possibilities offered by the number of operating cell or zones as well as the previously-mentioned minimum indexing spacing, it is possible to reproduce every optional indexing sequence.

With the described drive mechanism or arrangement a secondary drive or power can be removed or tapped-off at a single or several locations, namely, at any one or at each operating zone or cell, in order to displace in stepwise manner an operable member which is to be driven, or a plurality of such members, whereby with the movement of one or each of the members the introduced indexing sequence can again be reproduced. If a plurality of such operable members are driven, for example a single one by each operating zone or cell, then such undertake their movement with a time-delay in a so-called wave-like manner by virtue of the predetermined indexing sequence. For this reason, the described drive mechanism can also be used to advantage for driving the warp thread control or the weft thread control of weaving looms, particularly wave weaving looms. This possibility shall be explained with greater particularity hereinafter.

It, now, the last operating zone or cell of a row is connected with the first operating cell of the same row through the agency of a starter mechanism, as already suggested, after a predetermined indexing sequence has already been introduced at the row of operating cells, then, and as should be self-evident, the indexing sequence which has already been introduced to the first operating cell is returned and, therefore, again travels through the row of operating cells or zones. In other words, an introduced indexing sequence is thus stored in a closed row of operating zones or cells, that is, a closed system is provided. Consequently, the driven member or members execute a periodic motion determined by the indexing sequence or repetition. A change-over to- .a different indexing sequence is readily possible if the closed row of operating zones or cells are temporarily opened, that is, the operable connection between the terminal operating cell and the initial or first operating cell is interrupted, and there is introduced a new indexing sequence or repetition, whereupon the row of operating zones can again be closed.

Since in the following description only the arrangement of the operating cells is important for understanding the invention, it is advantageous to represent such by symbols. In the selected schematic representation an operating cell or zone is represented in each case by a surface enclosed by full-lines forming a block, such block being divided by a dashed line into a control portionlying above such line in the drawing-and a drive portion beneath such line. Thus, FIGURE 2 depicts such an operating cell 26 incorporating the control portion 26' and the drive portion 26". The arrow 27 appearing in the control portion 26' schematically represents an indexing command performed by operating cell 26 and delivered to the subsequent operating cell.

In FIGURE 3 there is depicted an opera-ting cell 29, the control portion 29' of which is operatively connected with the control portion of two further operating cells by means of suitable starter mechanisms. Consistent with the foregoing it will be understood that, the arrow or arrow portion 27 represents the executed indexing command, and the arrows 27 and 27" respectively, the transmitted indexing commands.

If power is tapped-01f from an operating cell or zone, then such power, as depicted in FIGURE 4, according to which an operating cell 30 transmits an indexing corn mand represented by arrow 27 to a neighboring operating cell, thus simultaneously transmits the indexing step via a power take-01f or secondary drive portion 31 to an operable member to be displaced. Regarding the operable member to be displaced, in the present situation, such is assumed to pertain to a loom harness, schematically represented in FIGURE 5 by the element bearing reference character 32. FIGURE 6 depicts the operating cell 30 of FIGURE 4 with the loom harness 32 driven by such operating cell.

The individual operating cells 26 can be arranged in open and closed rows. With a so-called closed row of cells the first operating cell of the row is operatively connected with the last, so that with this drive arrangement the indexing sequence or repetition always travels in a closed loop or cycle, hence, therefore, provides what may be conveniently considered as a closed indexing sequence storage system.

Such a storage system, that is a closed row of operating cells, is also depicted in FIGURE 7, wherein the operating cells 26 are arranged in a circle, and without the use of an actual feedback coupling form a closed row of operating cells. Also, in this case the drive portions 26" travel in synchronism with respect to one another and the cont-r01 portions 26' are operably connected with one another by starter mechanisms. By means of one of the operating cells 26, specifically, for example, the operating cell 30 it is possible to drive'a loom harness 32 which, then, executes a periodic motion corresponding to the stored indexing step sequence or command.

Now, in FIGURE 8 there is depicted a closed row of operating cells 30, with each such cell driving a harness 32. In this instance, such drive arrangement can, for example, relate to the drive of a row of harnesses 32 of a wave weaving loom, since these harnesses 32 driven by this drive arrangement respond to one and the same indexing command which is delayed in time, as previously explained, and thereby carry out the desired Wave motion.

With the drive arrangement according to FIGURE 9, the operating cells 26 provided with one operating cell 29 form a storage means, wherein the aforesaid operating cell 29 is connected in appropriate manner, and as will be further explained shortly, to the control portion of the first operating cell, designated by 30 of a row of cells embodying individual operating cells 30, in the man ner of FIGURE 8. All of the operating cells are sy-nchronously driven. Furthermore, each operating cell 30 drives a harness 32. An indexing step sequence or harness program command stored in the closed storage mechanism or means 35 embodying the operating cells 26, 29 of this embodiment, is delivered to the operating cells 30, and thereby to the harnesses 32.

The present invention is based upon the aforedescribed arrangement. In FIGURE 9, in accordance with the same principles as in FIGURE 8, there is illustrated the control for a single row of harnesses, wherein however, according to the invention an additional device, the unweaving drive or transmission is operably connected between a control portion and the row of harnesses 32. It is assumed that the illustrated harnesses 32 are divided with the same distribution throughout the weaving or cloth width, as such is clearly shown in FIGURE 10.

Now, in FIGURE 10 the previously mentioned weavover, such synchronously,

7 ing operation at a wave weaving loom is schematically illustrated. The shuttles 33 to 33 are distributed with an equal spacing over the entire weaving width. For convenience in illustration, in this figure the weft threads have been omitted and the warp threads depicted as dots. The shuttles 33 to 33 should, for instance, move from the left to the right of the drawing, the warp threads always being controlled in their position via the harnesses 32 of a harness change mechanism 35 such that, in each instance, they reach their maximum deviation when the shuttle is aligned with the relevent Warp thread. Morewarp threads change their position rearwardly of the shuttle, in so doing interlacing or tying the weft threads, as is known to the art. Thus, between each two successively following shuttles there always appears a warp thread cross-over location A, B, C, and so forth. Consequently, each harness of FIGURE 9, thus, always controls the warp the shuttle. In reality, still further harnesses are provided with the appropriate phase displacement between the illustrated harnesses, yet for convenience in illustration such have been omitted from the drawing.

As schematically depicted in FIGURE 9, the control component of the wave weaving loom under consideration comprises a command or impulse storage mechanism 35 and the harness change mechanism or unit 36.

The drive for both mechanisms 35 and 36 takes place and, it is assumed that the storage mechanism 35 is driven via the drive of the harness change mechanism 36 and this drive is independently driven.

As already briefly described, an impulse sequence or command can be stored in the impulse storage mechanism 35 for programming the harness motion, the impulses of which travel in a closed cycle with running of the drive of such storage mechanism, specifically in the direction denoted by the arrows. The commands or impulses are delivered to the harness change mechanism 36 via the operating cell 29. Each command or impulse then moves in stepwise manner through the harness change mechanism 36, in the direction of the arrows in the drawing, in other words, from left to right, bringing about a harness change in each operating cell thereof.

In the program storage mechanism 35 there is stored the maximum possible number of impulses X Xi These impulse or command numbers or command X has just entered the operating cell 29. The impulse sequence X X X X appearing at the same moment in the cells 30 to 30 of the harness change mechanism 36 are conveniently depicted in the individual cells. These impulses or command numbers should signify that the relevent harnesses 32 have just performed a movement corresponding to these impulses. With the next indexing step the impulse X moves out of the storege mechanism 35 into the cell 30 of the harness change mechanism 36 and the entire row of impulses in the aforesaid harness change mechanism 36 wanders through one step towards the right. In the storage mechanism 35 the command or impulse X then assumes the position of the command or impulse X in the cell 29, and so forth. The foregoing description individual cells.

generally covers the principle control operation during weaving.

The unweaving drive 37 connected between the harness change mechanism 36 and the impulse or proof rotation of the drive coming from the harness change mechanism 36, transform such into a stepwise drive and additionally step-down or speed-reduce the same. The

-reversal of the direction of the drive, means that the harness programming command or impulse sequence in the storage mechanism 35 will reverse its direction of thread in a position above or beneath travel, in other words, move opposite to the direction of the arrows through such storage mechanism. Further, it should stepwise transform the drive of the storage mechanism 35, whereby each resulting drive step corresponds to a further travel of the command or impulse from one operating cell to the next, and finally the drive must be stepped-down, it should thus be in a ratio of lzn. At this point, the value of n can still be left undetermined, yet will be considered shortly. The speed reduction should effect that the storage mechanism 35 moves through one step and then remains idle until the next indexing step for the time (n-l). Since the drive of the storage mechanism 35 now occurs in the opposite direction. the stored commands or impulses also wander in the opposite direction and in reverse sequence out of the cell 29.

However, at the drive for the harness change mechanism 36 nothing has been changed by the unweaving drive or transmission 37, just as before the introduced commands or indexing impulses for harness motion must travel through the harness change mechanism 36 in the direction of the arrows, and in order that they can do such its direction of rotation must be maintained. Thus, during unweaving the direction of rotation of the impulses coming from the storage mechanism 35 and entering the harness change mehanism 36 must be reversed. Specific details of the manner in which such requirements can be complied with will be considered fully at a later point in the description. At this time, however, in order to be 'able to fully comprehend the underlying principles of the inventive method the assumption that the unweaving drive possesses these characteristics is sufificient.

Considering now more specifically the inventive unweaving operation, it will be understood that to implement such the unweaving drive 37 depicted between harness change mechanism 36 and storage mechanism 35 should be switched to unweaving. In so doing, the storage mechanism 35 is driven in stepwise manner in the opposite direction. This means that with a subsequent indexing step the command or impulse X once again arrives via the cell 29 in the mechanism 36 and wanders with each indexing step through one cell 30 further to the right. In accordance with requirements, and as previously explained, the storage mechanism 35, however, remains at standstill for the next n-1 indexing steps, only the harness change mechanism 36 moves further. In other words, the impulse X after these 71- indexing steps, is located in the n cell from the left, in this case cell 30 having passed through all previous cells located to the left without a new indexing impulse or command, in this case the impulse X having followed.

The meaning of the step-down or reduction ratio 1:11 is now readily comprehensible. Specifically, the command or impulse should have moved through the entire weaving or fabric width by the time the next command or impulse is introduced to the harness change mechanism 36 by the storage mechanism 35. Since, however, a given number of shuttles 33 33 33 etc. are uniformly distributed over the entire weaving width, .the value It is dependent upon the number of shuttles. Thus, in the present physical construction n amounts to 8. It will fur ther be appreciated that impulse X is thus introduced two times. The first time during forward running, the second time during the first step backwards (unweaving). As a result, the harness program controlled by the first command or impulse X is eradicated since each impulse for each harness 32 signifies a change in position. All harnesses 32 to 32 having moved twice by virtue of the impulse X are thus again brought back into the same position they assumed prior to the first impulse X Fun thermore, since the second impulse X (the prime marking conveniently denoting reverse motion of such impulse during unweaving) moves up to the harness 32 without a new impulse being introduced into this row of harnesses 32, to 32 all harnesses of the row appear at the side at which they have been brought by the impulse X thus they all assume the same position.

In FIGURE 9 only a single row of harnesses 32 to 32 has been depicted. However, it will be appreciated that in order to weave a plurality of rows always appear behind one another, and the unweaving drive is simultaneously effective upon all rows of harnesses and storage mechanisms, as was the case described for a single row. The result is that at the end of the described operation all harnesses of one row assume the same position, that is, throughout the entire weaving width the same group distribution (up or down) appears for all harnesses behind one another. Consequently, in contradistinction to the shed shown in FIGURE there now appears the shed depicted in FIGURE 11.

The operation of unweaving will best be understood by referring to FIGURE 12. A warp thread chain 38 with shuttles 33 and weft threads 3? is schematically illustrated in FIGURE 12. It is assumed that at location X there has been ascertained that a weft thread has ruptured. The weaving loom has been switched-over to unweaving, at the moment of switching-over, the impulse or program storage mechanism 35 and the harness change mechanism 36 have assumed the position depicted in FIGURE 9, with the corresponding position of the shuttles being shown in FIGURE 12. The shuttle 33 has already passed through the entire weaving width by virtue of its program impulse X At a distance in back of shuttle 33 there is situated the shuttle 33 which with its program X has just arrived up to the location of the harness 32 and so forth, until reaching the shuttle 33 which has just been served at the beginning of the fabric or weaving width by the harness 32 via the cell with its program X This command or impulse X is thus already delivered to the harness change mechanism 36.

It is once again mentioned that nothing has changed in the mode of operation of the harness change mechanism 36 during switching-over to unweaving, that is, the shuttles travel further through the shed in the direction of the arrows. Moreover, with the firs-t indexing step after switching-over, the shuttle 33 will have completely deposited its thread and moved out of the shed. The shuttle 33 will be forwardly advanced to the right through one step until reaching the position 1, likewise all other shuttles move through one step to the right; also the shuttle 33 which at this time has deposited its weft thread up to position 7. At the previous location of shuttle 33 that is, at position 8, there now appears a shuttle 33 It will be appreciated, however, that for such shuttle 33 and all subsequent shuttles the delivery of weft thread has been cut-off in conjunction with the switching-over operation, so that these last-mentioned shuttles move empty through the shed. It will be recalled that the first impulse X was associated with the shuttle 33 Since, now, with the switching-over to unweaving the impulse X is once again introduced by the storage mechanism into the harness change mechanism 36, this second impulse X (rearward) is associated with the shuttle 33 without thread. With each further switching or indexing step all shuttles move one place further to the right, so that after seven indexing steps the shuttle 33 has also completely inserted its weft thread. However, with each indexing step the first threadless shuttle 33 has also travelled one step to the right and with it the second impulse X which has again opened the shed closed by the first impulse X During these seven indexing steps no further impulse is introduced into the harness change mechanism 36, since it will be remembered the storage mechanism 35 has remained at standstill during these seven steps. At the end of these total eight indexing steps the position illustrated in phantom lines in FIGURE 12 appears. The Weft thread 39 (the sub-numeral applied to the weft threads denoting the relevant command or impulse, here X tied or interlaced due to the harness change brought about by the impulse X is now disposed completely free in the shed, so that it can be effortlessly removed. With the subsequent indexing step the second impulse X (remember that the prime marking denotes the reverse moving command or impulse) is introduced into the harness change mechanism 36. This impulse X again travels across the entire weaving width and again opens the shed closed by the first impulse X so that when the impulse X has passed through, the weft thread 39 tied by the harness change effected by impulse X is also disposed in an open shed and can be removed. The same process occurs for all further weft threads which are to be withdrawn from the previously woven fabric. The loom always travels eight indexing steps forward when the unweaving drive is switched-over and the delivery of weft thread cut-off, whereby the program stored in the storage mechanism 35 is moved back through a respective position and for each eight indexing steps only one command or impulse is delivered to the row of harnesses 32. At the end of this operation there can always again be removed a thread which has been thus laid free. This occurs for such time until the place of rupture has been reached, and upon switching-out the unweaving drive it is possible to again operate in the normal manner.

In order to more fully explain the inventive unweaving method certain characteristics for the unweaving drive or transmission were pre-supposed. It will be recalled that this unweaving drive should transform in stepwise manner the drive for the storage mechanism 35 with reversed rotational sense and gear such down in proportion to the number of shuttles.

An example of how the required stepwise, steppeddown, power take-off is achieved from a continuous rotational movement has been schematically depicted in FIG- URE 13. At location D there enters the drive for the unweaving transmission or drive 37 of FIGURE 9 and continuously rotate-s a shaft 50 provided with both of the wheels or gears 51 and 52. The gear wheel 51 rotates a pair of cam disks 54, 54 via a second gear 53 and the shaft 62. The pair of cam disks 54, 54', in turn, are in engagement with a toothed disk assembly comprising the toothed disks 55, 55', respectively, and from this location a shaft 56 leads to a pair of wheels or disks 57, 57', the latter in turn acting upon the further disks 58, 58' respectively. The disks 58, 58' are rigidly mounted upon a shaft 59 provided with a gear 60 having a recess 61 in comparison with the gear 52 and functions as an indexing or switching element which is driven by the gear 52.

The stepwise, power take-oft" occurs at location E. The shaft 50 with both of its driving gears 51, 52 is thus continuously driven, at D, by the drive of the harness change mechanism. Consequently, the shaft 62 also continuously rotates and with it the cam disks 54, 54. This cam disk assembly 54, 54 is composed of two congruent portions, and each disk 54, 54' possesses a tooth-like entraining member 54a, 54b respectively, and such opposite a respective recess 54c, 54d. Both disks 54, 54 are displaced with respect to one another about so that the entraining member of one disk is always located above or below the recess of the other disk. This cam disk assembly 54, 54' is in engagement with the toothed disk unit 55, 55'. The disk unit 55, 55' is again of bipartite construction and each disk portion 55 and 55' carries five teeth for example, distributed with the spacing of a tooth width about the periphery of the relevent disk. Both disks 55, 55' are displaceably mounted at gaps so that they form a toothed disk unit, as shown, the teeth of which are alternately arranged in an upper and lower plane. The entrainment means 54a, 54b of the cam disk pair 54, 54' during rotation entrain the toothed disk unit 55, 55' via the teeth thereof. On the 11 one hand, the teeth and, on the other hand, both entrainment means are appropriately configured.

In the illustrated embodiment of FIGURE 13 the flank 63 of the entrainment means 54a of the cam disk 54 is shown as it just imparts an accelerated movement to the tooth 64 of the disk 55. The subsequent tooth 65 disposed in the same disk plane serves as slip safeguard. However, the tooth located in the lower disk 'plane between both of these teeth can also in cooperative working relation with the recess in the disk 54 be employed as a safeguard against slip. During the next half revolution of the disk assembly 54, 54 the entrainment means 54b of the disk 54 drives the tooth 64, and so forth. Thus, in the illustrated embodiment with five complete revolutions of the gear member 53, the toothed disk 55, 55 rotates once around and such stepwise in ten steps. The wheels or disks 57, 57' partake in this movement.

Both of the disk pairs 57, 57 and 58, 58' form together a drag coupling, wherein the dragging portion and the dragged portion are again of bipartite construction. In so doing, the one coupling portion 57, 58 again carries out the operating function i.e., the drive and braking, whereas the other coupling portion 57', 58 serves as the protection or safeguard against slip. The cam 66 of the disk 57 drives the disk 58 via its tooth 67. In the illustrated construction, during rotation of the toothed disk unit or assembly 55; 55' the flank 66' imparts an accelerated rotational movement to the tooth 67. However, with the drive of the disk 58 the gear also receives an impulse via the shaft 59, thereby placed into operable engagement with the drive gear 52. The latter rotates continuously and entrains the gear 69 and thereby the disk 58 for one revolution, while the disk 57 in the meantime has again remained at standstill.

7 By virtue of the disks 54, 54' both tooth disks 55, 55' are continuously further indexed through a respective half-division of a disk. In so doing, the disk 57 with the cam 66 rotates therewith and the flank 66', during each revolution, comes once into engagement with the tooth 67. More precisely, the flank 66' at the end of such an indexing step, when the shaft 56 is again at standstill for a period of time, comes exactly to standstill in the illustrated position in front of the tooth 67 and during the next step entrains such from the start.

The times for the individual movements are selected such that shortly before the end of this rotation initiated thereby, the elements seated upon the shaft 59 have also again started the shaft 56 in such a manner that the flank 66", upon rea-ching the greatest velocity, meets the flank 67' of the tooth 67, which in this moment has the same peripheral speed. The flanks 66 and 67 thus come to bear against one another Without impact and the flank 66", which subsequently is again delayed to zero, in this manner also brakes the disk 58, thereby bringing the gear 60 to standstill in the illustrated position. Such remains idle for such length of time until the disk 57 has again performed a complete revolution. Then the entire process starts again from the beginning. The disk-s 57' and 58' thus have the function of undertaking the momentary blocking in the other direction, as Well as blocking of the gear 60 during the remaining rotation of the disk 57. Moreover, for each complete revolution of the shaft 56 the shaft 59 likewise performs a complete revolution, yet with constant velocity and shorter acceleration at the beginning, as well as delay at the end.

Depending upon the selected transmission or gear ratio it is, therefore, possible to select the speed of rotation as well as the period of standstill appearing between a revolution of the gear 60. Such must be accommodated to the program storage mechanism 35 (FIGURE 9) as well as the fabric or weaving width. The power take-off, at E, of this transmission or drive leads to the drive of the program or impulse storage mechanism 35.

v, The physical construction of such an inventive drive explained in conjunction with the schematic illustration of FIGURE 13 is depicted in FIGURE 14. In addition to the drive for driving the storage mechanism 35 there is further illustrated in FIGURE 14 the coupling portion for the feedback of the impulse or command from the storage mechanism 35 to the harness change mechanism 36, and, more specifically, for a row of harnesses.

It will be recalled that it was previously mentioned that this unweaving transmission or drive 37 is connected between the harness change mechanism 36 and impulse or program storage mechanism 35. During weaving it transmits the drive from the harness change mechanism 36 directly to the impulse storage mechanism 35 and the impulse stored in such back into the harness change mechan1sm.

For this purpose the shaft 76 of the harness change mechanism 36 is coupled to the drive shaft 49 of the storage mechanism 35 through the intermediary of a coupling 77, 78. The stepwise power take-off of the storage mechanism 35 is transmitted from its shaft 70 directly to a shaft 71 of the harness change mechanism 36 via reversing gear means providing a coupling which will more fully be described hereinafter. Thus, two transmission paths are provided. The one for the drive of the storage mechanism 35 comes out of the harness change mechanism 36,at D, and at E leads into the storage mechanism 35; the other for the power take-off from the storage mechanism 35 arrives from such at F, and at G leads to the harness change mechanism 36. During weaving the movement transmission takes place directly, during unweaving there is switched-in the unweaving drive and couplings.

The unweaving drive 37 which has already been described as to its mode of operation serves to drive the storage mechanism 35 during unweaving. This unweaving drive is driven by the gear 51 and the power take-off takes place via the shaft 59 (FIGURE 13). In order to drive the gear 51 a coupling gear or wheel 79 is loosely pushed onto the shaft (FIGURE 14), which during weaving is stationary and during unweaving rigidly coupled for rotation via the coupling portion 77 with the shaft 76, so that the gear 51 is driven.

Generally, all of the shafts of the drive depicted in FIGURE 13 are constructed as hollow shafts which are mounted to be readily rotatable upon stationary shafts and at the ends of which the relevent gears or disks are seated. Moreover, the same reference numerals have here again been employed for the same or analogous elements, so that a repeated description of the drive would appear unnecessary. The power take-off of the transmission or drive is removed from the gear 60 in FIGURE 13, which was rigidly connected for rotation via the shaft 59 with the pair of disks 58, 58'. Consequently, and as illustrated in FIGURE 14, the gear 60, the hollow shaft 59 and the disks 58 and 58' form an assembly which is readily rotatable about a shaft. Further, the shaft 59 carries an additional gear 86 meshing with a further gear 80. This gear 80 is loosely pushed onto the drive shaft 49 for the storage mechanism 35 and can be rigidly connected for rotation with the aforesaid shaft by means of the coupling portion 78. If the shafts 76 and 49 are disengaged from one another, then, there takes place the 7 drive of the storage mechanism from the shaft 76 via the coupling portion 77, gear 51, the described stepping drive or transmission, then via its power take-off shaft 59, gears 86 and 80, and further, via the coupling portion '78 and shaft 49.

The coupling for the shafts 49, 76 can consist of a coupling portion 77 displaceable upon shaft 76 and rigidly connected for rotation therewith, this coupling portion 77 can advantageously be displaced by an arm 83 of a coupling slide 81 along the aforesaid shaft 76, as well as a second coupling portion 78 rigidly connected with the shaft 49. During weaving both coupling portions 77 and 13 78 are in engagement, to thereby directly couple both of the shafts 76, 49, whereby both of the gears 79 and 80 remain idle since they are only loosely pushed onto the respective shafts 76, 49. The gear 80 is arranged to be displaceable along the shaft 49 and can be coupled with the coupling portion 78 by a second arm 84 of the coupling slide 81. In order to unweave the coupling portion 77 is displaced along the shaft 76 by the coupling slide 81 via the arm 83, and the gear 80 along the shaft 49 via the arm 84. In so doing, the direct coupling of the shafts 76 and 49 is interrupted, the shaft 76 rigidly connected for rotation with the gear 79 and the shaft 49 with the gear 80, and the stepwise or stepping drive or transmission thus switched-in.

The result of all of this is that, a rotational movement entering at D is now guided to the outlet drive shaft 49 via the described stepwise or stepping drive. This, thus, rotates stepwise and with reversed rotational sense, as already explained in detail. In this manner, it drives the storage mechanism 35 and thereby the shaft 70 coming from such rotates in the opposite or reverse sense. However, since the harness change mechanism 36 also travels in positive direction during unweaving, the sense of rtation through the illustrated reversing drive means R now placed in operation must be changed.

The impulses arrive at F from the storage mechanism 35 and are delivered at G to the harness change mechanism 36. It will be appreciated that these impulses themselves are rotational movements. The power take-off shaft 70 of the storage mechanism 35 during the weaving is again correctly coupled as to rotational sense with the drive shaft 71 of the harness change mechanism. Such coupling takes place via the reversing drive means R embodying a group of bevel gears 72, 73, 73and 74. The bevel gear 72 is connected for rotation with the shaft 70 and the bevel gear 74 with the shaft 71. Each of the other bevel gears 73 and 73 mesh with the bevel gears 72 and 74, both rotatably mounted upon the common shaft 87 in a housing 75. The housing 75 is operatively connected with the shaft 70 via the bevel gears 72, 73 and 73', whereas the shaft 71 can be directly connected for rotation with the housing 75 via the coupling 88.

During weaving the coupling 88 couples the shaft 71 for rotation to the housing 75. Thus, there exists a rigid connection of both shafts 70 and 71 via the housing 75 rotating therewith'and the transmission of movement from the one shaft 70 to the other shaft 71 takes place directly.

The rigid connection of the shaft 71 with the housing 75 is released in order to unweave. For this purpose the coupling 88 on the shaft 71 is indeed rigidly connected for rotation with such, yet displaceably arranged thereupon. The coupling 88 is actuated via a third arm 82 of the coupling slide 81. Upon releasing the coupling between shaft 71 and housing 75 such is simuultaneously blocked, for example, through the intermediary of a nose 85 provided at the coupling slide 81 which engages into a recess or gap 75 at the housing 75. Both shafts 70 and 71 are thus connected through the agency of the bevel gears, resulting in a reversal of the direction of rotation, so that a rotational movement entering at F leaves the arrangement at G with the opposite sense of rotation.

The change-over from weaving to unweaving merely takes place by displacing the coupling slide 81. Reference is once again made to the fact that in FIGURE 14 only one feedback FG is illustrated, whereas in practice one such is necessary for each row of harnesses to be controlled.

It will be understood that with the unweaving drive illustrated by way of example, it is possible without difficulty to place a wave weaving machine in operation such that the inventive method for unweaving can be performed thereat. On the other hand, with the method of unweaving according to the invention, it is possible to reverse or run-back the control program at wave weaving looms until reaching the place of rupture of the thread or relevent defect, whereby the weft threads inserted in front of the place of rupture are laid free one after the other and can be removed with little effort, and upon repairing the place of rupture weaving can be continued exactly according to the prescribed pattern.

While there is shown and described present preferred embodiments of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practised within the scope of the following claims.

What is claimed is:

1. In a wave weaving loom, a plurality of shuttles weaving simultaneously, a controllable program storage mechanism for controlling harness motion, a harness change mechanism operably connected with said program storage mechanism, a transmission device capable of being switched-in between said program storage mechanism and said harness change mechanism for prolonging a program for controlling harness motion a number of repetitions equal to the number of shuttles employed during weaving.

2. In a wave weaving loom according to claim 1, said harness change mechanism and said program storage mechanism being constructed from indexing elements, said program storage mechanism being synchronously driven with said harness change mechanism, said program storage mechanism incorporating stepwise power take-ofi acting back upon said harness change mechanism for transmitting commands for harness change thereto, drive means for said program storage mechanism, said transmission device being constructed as a stepping transmission connectable with the drive means for said program storage mechanism.

3. In a wave weaving loom according to claim 2, further including coupling means arranged between the power take-off of the program storage mechanism and the harness change mechanism for delivering to the latter during weaving as well as unweaving indexing commands consisting of rotational impulses in a predetermined direction of rotation.

4. In a wave weaving loom according to claim 2, wherein said stepping transmission is simultaneously constructed as a reversing drive.

5. In a Wave Weaving loom according to claim 4, said transmission device constructed as a stepping transmission including a power take-off shaft which performs a complete revolution for each indexing step.

6. In a wave weaving loom according to claim 3, said coupling means arranged between the power take-off of the program storage mechanism and the harness change mechanism comprising a reversing drive rendered operable upon switching-in said transmission device for unweaving.

7. In a wave weaving loom according to claim 5, said transmission device further including a stepwise indexing member capable of being brought into operable engagement with the drive means for said program storage mechanism, starter means driven in stepwise manner by said drive means, said starter means releasing said stepwise indexing member during an indexing step and fixedly holding the same for a predetermined number of indexing steps. 7

8. In a wave weaving loom according to claim 7, wherein said stepwise indexing member comprises an indexing gear provided with a gap devoid of teeth, said drive means including a drive gear with which said indexing gear meshes.

9. In a wave weaving loom according to claim 8, said starter means for said stepwise indexing member comprising a stepwise driven drag coupling, said drag coupling incorporating a dragged portion rigidly connected for rotation with said indexing gear.

10. In a wave weaving loom according to claim 9,

wherein said drag coupling in addition to said dragged portion includes a dragging portion, both of which are of further including a stepwise coupling incorporating a dragged portion and a dragging portion, said dragging portion of said stepwise coupling being continuously driven, the dragging portion of said drag coupling being rigidly connected for rotation with the dragged portion of said stepwise coupling.

12. In a wave weaving loom according to claim 11, wherein said dragging portion of said stepwise coupling comprises cam disk means and said dragged portion thereof a toothed disk unit.

13. In a wave weaving loom according to claim 12, where-in said dragged portion and said dragging portion of said stepwise coupling are each of bipartite construction and mutually safeguard one another against slip.

14. In a Wave weaving loom according to claim 11, further including drive gear means with which sa-id dragging portion of said stepwise coupling is rigidly connected for rotation, said drive gear means being commonly driven together with said drive gear for said stepwise indexing member.

15. In a wave weaving loom according to claim 9, including a drive shaft for said harness change mechanism, a power take-off shaft for said program storage mechanism, said reversing drive comprising four bevel gears, one

bevel gear of which is rigidly connected for rotation with said power take-off shaft of said program storage mechanism, another bevel gear of which is rigidly connected with said drive shaft for said harness change mechanism,

and the remaining two bevel gears are mutually engageable via said one and another bevel gears, a housing in which said four bevel gears are housed, said housing being rigidly connected with said drive shaft for direct transmission of rotational movement to said drive shaft, means for blocking said housing for reversal of the rotational movement so that said drive shaft is only rotated by said power take-off shaft of said program storage mechanism via said bevel gears.

16. In a wave weaving loom according to claim 6 including a common coupling slide cooperating with said transmission device and reversing drive.

17. In a wave weaving loom, a plurality of shuttles 'weaving simultaneously, a controllable program storage mechanism for controlling harness motion, a harness change mechanism operably connected with said program storage mechanism, a drive for continuously synchronously driving said program storage mechanism with said harness change mechanism, a transmission device for unweaving of a fabric woven at the loom operably connectable between said program storage mechanism and said harness change mechanism for prolonging a program for con-trolling harness motion a number of repetitions equal to the number of shuttles employed during weaving, said transmission device incorporating means for reversing the direction of rotation of said drive for said program storage mechanism, means for stepping down said drive in relation to the number of shuttles, and means for transforming said drive into a stepwise drive.

18. Method for unweaving at a wave Weaving loom wherein during weaving the weft threads are interlaced with the warp threads at a location between each two shuttles following one another in succession, with each individual shuttle moving at a spacing from one another into the warp threads having associated therewith its own harness change program effective at at least one driven harness change mechanism, which method comprises the steps of: cutting-out the delivery of weft thread to the shuttles upon ascertaining a faulty condition in the previously woven fabric, delivering into the harness change mechanism in reverse sequence the commands for harness change previously fed into such harness change mechanism during weaving of the fabric, causing each command for harness change to repeat between each two successive harness change commands a number equal to the number of shuttles employed for weaving the fabric, then removing the weft thread laid free in the shed now open throughout the entire fabric width after each command has travelled through the harness change mechanism, and repeating the aforedescribed method steps until the location of the faulty condition is reached.

19. Method for unweaving at a wave weaving loom wherein during weaving the weft threads are interlaced with the warp threads at a location between each two shuttles following one another in succession, with each individual shuttle moving at a spacing from one another into the warp threads having associated therewith its own harness change program effective at at least one harness change mechanism, which method comprises the steps of: cutting-out the delivery of weft thread to the shuttles upon ascertaining a faulty condition in the previously woven fabric, delivering into the harness change mechanism in reverse sequence the commands for harness change previously fed into such harness change mechanism during weaving of the fabric, while controlling the time interval between each two successive harness change commands in relation to the number of shuttles employed for weaving the fabric, in order to open the shed for the last inserted weft thread to thus unlace the latter, then removing the weft thread thus laid free in the shed now open throughout the entire fabric width after each command has travelled through the harness change mechanism, and repeating the aforedescri-bed method steps until the location of the faulty condition is reached.

References Cited by the Examiner UNITED STATES PATENTS 2,123,267 7/1938 Wentz 139326 2,639,732 5/1953 Moessinger 139-1.4 2,640,504 6/1953 Blanchard l39--l.4 3,160,177 12/ 1964 Williams et al 13924 ROBERT R. MACK-BY, Primary Examiner.

S, JAU DON, Assistant Examiner. 

1. IN A WAVE WEAVING LOOM, A PLURALITY OF SHUTTLES WEAVING SIMULTANEOUSLY, A CONTROLLABLE PROGRAM STORAGE MECHANISM FOR CONTROLLING HARNESS MOTION, A HARNESS CHANGE MECHANISM OPERABLE CONNECTED WITH SAID PROGRAM STORAGE MECHANISM, A TRANSMISSION DEVICE CAPABLE OF BEING SWITCHED-IN BETWEEN SAID PROGRAM STORAGE MECHANISM AND SAID HARNESS CHANGE MECHANISM FOR PROLONGING A PROGRAM FOR CONTROLLING HARNESS MOTION A NUMBER OF REPETITIONS EQUAL TO THE NUMBER OF SHUTTLES EMPLOYED DURING WEAVING. 